Customize a d3 plugin to add a specific feature

I'm looking for someone who could add a specific functionality to a d3 plugin available on github. Generally speaking, the plugin helps plot data in node-link form, and what's missing is the option to add invisible nodes and links. The purpose is to align all nodes on the same vertical line, which doesn't happen as it is since different data points are of different sizes. I know it's a little obscure, but specific details will be given in PM.